Computerized fetal heart rate analysis in the prediction of myocardial damage in pregnancies with placental insufficiency.

OBJECTIVE: To evaluate the reliability of fetal heart rate (FHR) parameters analyzed by computerized cardiotocography (cCTG) in predicting myocardial damage in pregnancies with placental insufficiency. STUDY DESIGN: We evaluated 38 patients with placental insufficiency detected before 34 weeks of gestation. All patients underwent 30 min of cCTG (Sonicaid Fetal Care, version 2.2) and Doppler of umbilical artery, middle cerebral artery, and ductus venosus. Umbilical vein blood samples were collected at birth to determine fetal cardiac Troponin T, and a ≥0.09ng/ml value was deemed a sign of myocardial damage. RESULTS: The fetuses with myocardial damage (39%) showed significantly increased values of umbilical artery pulsatility index z-score (P=0.003), ductus venosus pulsatility index z-score (P=0.007), basal FHR (P=0.033) and periods of low episodes (P=0.038). The number of small accelerations and the short-term variation (STV) were significantly reduced in the group with myocardial damage (P=0.013 and P=0.003, respectively). Logistic regression analysis identified STV and gestational age at delivery as independent predictors for fetal myocardial damage, with area under ROC curve of 0.91. CONCLUSIONS: Computerized cardiotocography parameters may be useful in the management of early onset placental insufficiency, and the association of STV with gestational age could play a role in detecting myocardial injury in pregnancies with placental insufficiency.

Influence of fetal acidemia on fetal heart rate analyzed by computerized cardiotocography in pregnancies with placental insufficiency.

OBJECTIVE: To determine the influence of fetal acidemia on fetal heart rate (FHR) parameters analyzed by computerized cardiotocography (cCTG) in pregnancies with placental insufficiency. METHODS: This was a cross-sectional study of 46 pregnancies with placental insufficiency between 26 and 34 weeks gestation by abnormal umbilical artery Doppler [pulsatility index (PI) > 95th percentile]. RESULTS: Twenty fetuses had acidemia at birth, pH < 7.20 (43.5%) and 26 had normal pH (56.5%). In the analysis of FHR parameters, fetal movements (FM) per hour was significantly lower in the group with acidemia (median = 2) when compared with the group with normal pH (median = 15, p = 0.019). The values of pH correlated positively with FM (ρ = 0.35; p = 0.019, 95% CI: 0.061 to 0.577) and basal FHR (ρ = 0.37, p = 0,011, 95% CI: 0.090 to 0.597) and negatively with the ductus venosus (DV) PI for veins (PIV) z-score (ρ = -0.31, p = 0,036, 95% CI: -0.550 to -0.021). Logistic regression showed that the DV PIV z-score (p = 0.0232) and basal FHR (p = 0.0401) were independent variables associated with acidemia at birth. CONCLUSIONS: The present results suggest that cCTG parameters may be useful in the management of cases with early onset placental insufficiency in association with Doppler velocimetry assessment, and that basal FHR and DV-PIV are most clearly in association with acidemia at birth.